The seed coat serves as the primary protective barrier, offering mechanical and chemical defense for the embryo. It contains various metabolites, including phenolic compounds, which can be oxidized by polyphenol oxidase (PPO) to form oligomers. In this study, we heterologously expressed a 515 amino acid protein derived from wild pea (Pisum elatius), omitting its N-terminal signal sequence, and analyzed its biochemical properties. The recombinant PeaPPO required sodium dodecyl sulfate (SDS) for activation and exhibited activity between pHs 5.2 and 7.0, peaking at pH 6.0 with 0.25 mM SDS. Tropolone and its isomer thujaplicin were the most effective inhibitors. PeaPPO catalyzed reactions with seed coat-derived substrates, displaying activity toward phenols, catechols, and pyrogallols, with the highest affinity for catechols. Principal component analysis of LC-MS/MS-derived phenolic profiles demonstrated that PPO+ and ppo- genotypes differ significantly in their accumulation of PPO substrates and inhibitors. These findings confirm that PeaPPO possesses both monophenolase and catechol oxidase activities, identifying it as a tyrosinase.

• Keywords
• legumes, pea, phenolics, polyphenol oxidase, seeds, tyrosinase,
• MeSH
• Phenols * metabolism   chemistry   MeSH
• Pisum sativum * enzymology   genetics   chemistry   MeSH
• Catechol Oxidase * metabolism   genetics   chemistry   MeSH
• Kinetics MeSH
• Recombinant Proteins metabolism   chemistry   genetics   MeSH
• Plant Proteins * genetics   chemistry   metabolism   MeSH
• Seeds * enzymology   chemistry   genetics   MeSH
• Substrate Specificity MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Phenols * MeSH
• Catechol Oxidase * MeSH
• Recombinant Proteins MeSH
• Plant Proteins * MeSH

Pod dehiscence facilitates seed dispersal in wild legumes while indehiscence is a key domestication trait in cultivated ones. However, the evolutionary genetic mechanisms underlying its diversity are largely unclear. In this study, we compared transcriptomes of two warm-season (Glycine spp. and Phaseolus spp.) and two cool-season (Pisum spp. and Medicago ruthenica) legumes in analysis of dehiscent and indehiscent pod genotypes. Differentially expressed genes in AP2/ERF-like transcription factors and seven structural gene families, including lactoperoxidase, laccase, and cellulose synthase-interactive proteins, which are involved in secondary cell wall component accumulation, were identified to exert key roles in pod dehiscence variation. In accordance with this, higher lignin and cellulose contents were observed in pod secondary cell wall of dehiscent accessions of soybean and pea; however, the variation patterns of lignin polymers in soybean (accumulation) and pea (proportion) differed between dehiscent and indehiscent pods. Moreover, genome-wide comparative analysis revealed that orthogroups represented <1% of all identified differentially expressed genes could be traced among the four genera of legumes, while recruiting paralogous members may constitute the genetic robustness of legume pod dehiscence. This study compared the genetic mechanism among several legumes in pod dehiscence formation and revealed a compensating role of paralogous redundancy of involved gene families in seed dispersal, which can guide crop breeding.

• Keywords
• domestication, gene expression, genetic basis, legumes, lignin, pod dehiscence,
• MeSH
• Cell Wall metabolism   genetics   MeSH
• Fabaceae * genetics   MeSH
• Lignin metabolism   MeSH
• Multigene Family MeSH
• Gene Expression Regulation, Plant MeSH
• Plant Proteins genetics   MeSH
• Seeds genetics   MeSH
• Transcriptome MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Lignin MeSH
• Plant Proteins MeSH

The physical dormancy of seeds is likely to be mediated by the chemical composition and the thickness of the seed coat. Here, we investigate the link between the content of phenylpropanoids (i.e., phenolics and flavonoids) present in the chickpea seed coat and dormancy. The relationship between selected phenolic and flavonoid metabolites of chickpea seed coats and dormancy level was assessed using wild and cultivated chickpea parental genotypes and a derived population of recombinant inbred lines (RILs). The selected phenolic and flavonoid metabolites were analyzed via the LC-MS/MS method. Significant differences in the concentration of certain phenolic acids were found among cultivated (Cicer arietinum, ICC4958) and wild chickpea (Cicer reticulatum, PI489777) parental genotypes. These differences were observed in the contents of gallic, caffeic, vanillic, syringic, p-coumaric, salicylic, and sinapic acids, as well as salicylic acid-2-O-β-d-glucoside and coniferaldehyde. Additionally, significant differences were observed in the flavonoids myricetin, quercetin, luteolin, naringenin, kaempferol, isoorientin, orientin, and isovitexin. When comparing non-dormant and dormant RILs, significant differences were observed in gallic, 3-hydroxybenzoic, syringic, and sinapic acids, as well as the flavonoids quercitrin, quercetin, naringenin, kaempferol, and morin. Phenolic acids were generally more highly concentrated in the wild parental genotype and dormant RILs. We compared the phenylpropanoid content of chickpea seed coats with related legumes, such as pea, lentil, and faba bean. This information could be useful in chickpea breeding programs to reduce dormancy.

• Keywords
• chickpea, dormancy, flavonoids, legumes, phenolic acids, seed coat,
• Publication type
• Journal Article MeSH

We showed that wild pea seeds contained a more diverse combination of bioactive GAs and had higher ABA content than domesticated peas. Although the role of abscisic acid (ABA) and gibberellins (GAs) interplay has been extensively studied in Arabidopsis and cereals models, comparatively little is known about the effect of domestication on the level of phytohormones in legume seeds. In legumes, as in other crops, seed dormancy has been largely or entirely removed during domestication. In this study, we have measured the endogenous levels of ABA and GAs comparatively between wild and domesticated pea seeds during their development. We have shown that wild seeds contained more ABA than domesticated ones, which could be important for preparing the seeds for the period of dormancy. ABA was catabolised particularly by an 8´-hydroxylation pathway, and dihydrophaseic acid was the main catabolite in seed coats as well as embryos. Besides, the seed coats of wild and pigmented cultivated genotypes were characterised by a broader spectrum of bioactive GAs compared to non-pigmented domesticated seeds. GAs in both seed coat and embryo were synthesized mainly by a 13-hydroxylation pathway, with GA29 being the most abundant in the seed coat and GA20 in the embryos. Measuring seed water content and water loss indicated domesticated pea seeds´ desiccation was slower than that of wild pea seeds. Altogether, we showed that pea domestication led to a change in bioactive GA composition and a lower ABA content during seed development.

• Keywords
• Desiccation, Legume, Maturation, Phytohormones, Pigmentation, Seed-coat,
• MeSH
• Arabidopsis * genetics   MeSH
• Domestication MeSH
• Gibberellins metabolism   MeSH
• Pisum sativum genetics   metabolism   MeSH
• Germination MeSH
• Abscisic Acid * metabolism   MeSH
• Seeds MeSH
• Plant Dormancy genetics   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Gibberellins MeSH
• Abscisic Acid * MeSH

Increasing the proportion of locally produced plant protein in currently meat-rich diets could substantially reduce greenhouse gas emissions and loss of biodiversity1. However, plant protein production is hampered by the lack of a cool-season legume equivalent to soybean in agronomic value2. Faba bean (Vicia faba L.) has a high yield potential and is well suited for cultivation in temperate regions, but genomic resources are scarce. Here, we report a high-quality chromosome-scale assembly of the faba bean genome and show that it has expanded to a massive 13 Gb in size through an imbalance between the rates of amplification and elimination of retrotransposons and satellite repeats. Genes and recombination events are evenly dispersed across chromosomes and the gene space is remarkably compact considering the genome size, although with substantial copy number variation driven by tandem duplication. Demonstrating practical application of the genome sequence, we develop a targeted genotyping assay and use high-resolution genome-wide association analysis to dissect the genetic basis of seed size and hilum colour. The resources presented constitute a genomics-based breeding platform for faba bean, enabling breeders and geneticists to accelerate the improvement of sustainable protein production across the Mediterranean, subtropical and northern temperate agroecological zones.

• MeSH
• Gene Amplification genetics   MeSH
• Genome-Wide Association Study MeSH
• Chromosomes, Plant genetics   MeSH
• Diploidy * MeSH
• Genetic Variation * genetics   MeSH
• Genome, Plant * genetics   MeSH
• Genomics * MeSH
• Recombination, Genetic MeSH
• Retroelements genetics   MeSH
• Genes, Plant genetics   MeSH
• Plant Proteins * genetics   metabolism   MeSH
• DNA, Satellite genetics   MeSH
• Seeds anatomy & histology   genetics   MeSH
• Plant Breeding * methods   MeSH
• DNA Copy Number Variations genetics   MeSH
• Vicia faba * anatomy & histology   genetics   metabolism   MeSH
• Crops, Agricultural * genetics   metabolism   MeSH
• Geography MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Retroelements MeSH
• Plant Proteins * MeSH
• DNA, Satellite MeSH